Question

在这个例子中是否可以使用javassist获取Spring方法注释？

@RequestMapping(value={"/start"}, method={org.springframework.web.bind.annotation.RequestMethod.GET})
public String showForm(Model model, HttpServletRequest request)

Answer 1

我希望我理解这个问题，你可以使用Java反射来解决它。

如果您知道方法和注释：

RequestMapping annotation = YourController.class.getMethod("showForm", Model.class, HttpServletRequest.class).getAnnotation(RequestMapping.class);

RequestMethod[] requestMethods = annotation.method();

如果您想要检索特定方法的所有注释：

Annotation[] annotations = YourController.class.getMethod("showForm", Model.class, HttpServletRequest.class).getAnnotations();

如果要检索具有给定注释的所有方法：

List<Method> methods = new ArrayList<>();
for (final Method method : YourController.class.getMethods()) {
    if (method.getAnnotation(RequestMapping.class) != null) {
        methods.add(method);
    }
}

或Java 8方式：

List<Method> methods = Arrays.stream(YourController.class.getMethods()).filter(method -> method.getAnnotation(RequestMapping.class) != null).collect(Collectors.toList());

Answer 2

例如，

 import javassist.bytecode.annotation.Annotation;
    :
 CtMethod m = ... ;
 MethodInfo minfo = m.getMethodInfo();
 AnnotationsAttribute attr = (AnnotationsAttribute)
         minfo.getAttribute(AnnotationsAttribute.invisibleTag);
 Annotation an = attr.getAnnotation("Author");
 String s = ((StringMemberValue)an.getMemberValue("name")).getValue();
 System.out.println("@Author(name=" + s + ")");

摘自官方文档：https://www.javassist.org/html/javassist/bytecode/AnnotationsAttribute.html

使用javassist获取Method注释

2 个答案: